Which doesn’t make it Linux, which is what op wants. It’s based on a BSD-based mach kernel. You might as well say someone asking for Linux should just run Irix, because hey, it’s UNIX!
Who cares about the kernel? That only matters for hardware support, which is going to be much better with macOS on mac hardware. Macs can easily run 99%+ of the software that people use linux for, because *nix. The only real reasons to require linux in this situation are ideological (free software/GPL vs proprietary Apple) and aesthetic (you're used to X/wayland/systemd/whatever system software and don't like Apple's solution). It would definitely be nice if Apple helped people out by documenting and releasing source for the bootloader and firmware to make it easier to install third-party OSes on their hardware... but they're not a hacker-hobbyist nonprofit doing it for the love, so why would they?
WSL is literally the Linux kernel running in a VM, so WSL is actually closer.
But you can have a Linux kernel running in a VM on macOS as well, and while it doesn't have something like WSL built-in, it provides enough foundation for others to build it: https://lima-vm.io/docs/